Well there are many variables. You just want a trac-lok rear you might find a good used 3.27 unit for around $350 plus shipping. Generally to have one built you have to consider the cost of the parts and labor.
If you put $200 into rebuild parts and need a core case which will generally cost $75 plus a good used Traction lock could cost another $125 easily. Then you need gears which are around $175 and the labor to build it which will vary. I generally charge $250 if that gives you an idea. Then you need to decide if you want an aluminum case which could cost you about $75 more.
Alan

You can use an 8.8 pumpkin from any MN12 T-Bird, Cougar, or MK VIII. There are plenty around. I'm surprised no one here has offerred you one yet. If you're going to swap gears, have a shop do it. If you're going to keep the stock 3.08s or 3.27s in the pumpkin you find, you could probably just freshen up the clutches and plop it in. I have a few IRS traction lok units and complete pumpkins with 3.27s, if you're interested. I'm in Southern California, so shipping could be expensive.

I live in a hicktown in canada. I could go to the guy who charged 2500 for a taurus tranny or to the guy who charged 2700 for an exploder tranny.

thats not my fault. The best way to get an honest answer is to ask whom ever is doing the work directly. Otherwise is almost a shot in the dark. If we tell you a price and you end up paying more, dont complain to us.

I posted in the wanted section and got a 3.27 TL unit, with about 20k on it, from a fellow member for $150. He was upgrading to higher gears and just wanted it to go to a nice home. So, the deals are out there, you just gotta be patient and make it known that you are looking.

well..... $200 for gears (maybe more after they're shipped to you), $200 for the rebuild kit after it's shipped.... $150 for the empty case, $150 for the track-lok UNIT, at least $250 for them to assemble the pumpkin. Who knows what kind of prices the shop charges...those are the internet prices. Even if it is rebuilt units, the shop is still going to charge you an arm and a leg.
That's $900 I think, then they're gonna charge you $80 an hour to remove old pumpkin, and charge you for differential fluid, and all the "time" it's gonna take them to put the driveshaft back in, etc. So for a shop to do it, and pay for the parts...doesn't surprise me.
If you research how to modify a mustang rear end...you might be able to find a cheap one on Corral.net/forums and have someone modify the side gears....and install it yourself.

*sigh* you arent gonna find a complete, fresh pumpkin with a trac lok in it for nothing. Decy Figuoera could build you one for a few hundred and ship it.....as could dirtydog. Heres a tip, be willing to spend money or dont complain.

My Pumpkin is fine except with no posi in it, why would another pumpkin with posi really need anything except for new clutches?I am quite capable of changing the clutches in it.I would just install a trac lok unit in my own rear end, but I do not think that I own a tool to measure accurately enough to put the ring gear back in the exact same place it was before removal. Or is it easier than I am thinking?

The clutches are oddly one of the parts if you were trying to do the job cheap you might reuse. The bearings,seals and crush sleeve must be replaced.
Alan

1. you wanted to change the diff in your car yourself and we advised you against it if you didnt have the proper tools and experience.
2. you complained to us that your local mechanic charges too much, why would you complain to us how much he charges? we cant change any of that.
3. then you wanted again to know how easy it would be to swap the locker and we again informed you that it would be dificult.
4. A "working" diff is different from one with a freshly built diff with new frictions, new seals, and new bearings.
5.I answered your question nicely the first time. We are unable to tell you how much work is to be done on your existing diff, since we stuck to the topic. There are a load of variables, including how much wear is on the existing trac lok, if you want to use a stiffer load spring, if you want to use new gears, if there is abnormal wear on the existing bearings.
6. All of us attempted to give you honest and credible answers and info and you blatently chose not to listen....which makes me wonder why you asked in the first place, if you dont want to use any of the info we provided, then why ask. A very good write up in the tech articles is available on how to swap out a pumpkin.
7. So, unless you are willing to do your own research with both a prospective mechanic doing the work and any necessary overhauling that would be needed on the prospective diff with thee trac lok, including your own installation, dont get upset at an answer or answers if they dont match your own hypothetical pipedream, then tough ****.

How much can I expect to pay for a trac loc rear to fit my 97 4.6 bird? I am in Canada. - That was your first post. Now, your best bet would be to call the shop that would do the work, your post was vague, so we had to guess as to what your intentions were.